VC: Use scoring function to select best attestation data when using multiple BNs. (#5101)

* Initial commit.

* Move score selection log statement to debug level.

* Fix proper float64 log format.

* Cleanup imports and legacy code.

* Address review comments.

* Address review comments.

* Fix scoring function.

* Address review comments.

* Address review comments 2.
Fix registerBlock post-rebase issues.

* Simplify innerLoop decision making.

* Make getAttestationDataScore() more testable.
Add tests for getAttestationDataScore().

* Add modified AllTests copy.

AllTests-mainnet.md

@@ -575,9 +575,10 @@ OK: 24/24 Fail: 0/24 Skip: 0/24
 OK: 1/1 Fail: 0/1 Skip: 0/1
 ## Validator Client test suite
 ```diff
++ getAttestationDataScore() test vectors                                                     OK
 + normalizeUri() test vectors                                                                OK
 ```
-OK: 1/1 Fail: 0/1 Skip: 0/1
+OK: 2/2 Fail: 0/2 Skip: 0/2
 ## Validator change pool testing suite
 ```diff
 + addValidatorChangeMessage/getAttesterSlashingMessage                                       OK
@@ -688,4 +689,4 @@ OK: 2/2 Fail: 0/2 Skip: 0/2
 OK: 9/9 Fail: 0/9 Skip: 0/9
 
 ---TOTAL---
-OK: 389/394 Fail: 0/394 Skip: 5/394
+OK: 390/395 Fail: 0/395 Skip: 5/395

beacon_chain/validator_client/api.nim

@@ -5,10 +5,11 @@
 #   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
-import chronicles
+import std/strutils
-import ../spec/eth2_apis/eth2_rest_serialization,
+import chronicles, stew/base10
-       ../spec/datatypes/[phase0, altair]
+import ".."/spec/eth2_apis/eth2_rest_serialization,
-import common, fallback_service
+       ".."/spec/datatypes/[phase0, altair]
+import "."/[common, fallback_service, scoring]
 
 export eth2_rest_serialization, common
 
@@ -35,12 +36,47 @@ type
     status*: ApiOperation
     data*: seq[ApiNodeResponse[T]]
 
+  ApiScore* = object
+    index*: int
+    score*: Opt[float64]
+
+  BestNodeResponse*[T] = object
+    node*: BeaconNodeServerRef
+    data*: ApiResponse[T]
+    score*: float64
+
 const
   ViableNodeStatus = {RestBeaconNodeStatus.Compatible,
                       RestBeaconNodeStatus.NotSynced,
                       RestBeaconNodeStatus.OptSynced,
                       RestBeaconNodeStatus.Synced}
 
+proc `$`*(s: ApiScore): string =
+  var res = Base10.toString(uint64(s.index))
+  res.add(": ")
+  if s.score.isSome():
+    res.add(shortScore(s.score.get()))
+  else:
+    res.add("<n/a>")
+  res
+
+proc `$`*(ss: openArray[ApiScore]): string =
+  "[" & ss.mapIt($it).join(",") & "]"
+
+chronicles.formatIt(seq[ApiScore]):
+  $it
+
+func init*(t: typedesc[ApiScore], node: BeaconNodeServerRef,
+           score: float64): ApiScore =
+  ApiScore(index: node.index, score: Opt.some(score))
+
+func init*(t: typedesc[ApiScore], node: BeaconNodeServerRef): ApiScore =
+  ApiScore(index: node.index, score: Opt.none(float64))
+
+func init*[T](t: typedesc[BestNodeResponse], node: BeaconNodeServerRef,
+              data: ApiResponse[T], score: float64): BestNodeResponse[T] =
+  BestNodeResponse[T](node: node, data: data, score: score)
+
 proc lazyWaiter(node: BeaconNodeServerRef, request: FutureBase,
                 requestName: string, strategy: ApiStrategyKind) {.async.} =
   try:
@@ -78,6 +114,18 @@ proc lazyWait(nodes: seq[BeaconNodeServerRef], requests: seq[FutureBase],
   else:
     await allFutures(futures)
 
+proc apiResponseOr[T](future: FutureBase, timerFut: Future[void],
+                      message: string): ApiResponse[T] =
+  if future.finished():
+    doAssert(not(future.cancelled()))
+    if future.failed():
+      ApiResponse[T].err($future.error.msg)
+    else:
+      ApiResponse[T].ok(Future[T](future).read())
+  else:
+    doAssert(timerFut.finished())
+    ApiResponse[T].err(message)
+
 template firstSuccessParallel*(
            vc: ValidatorClientRef,
            responseType: typedesc,
@@ -118,8 +166,7 @@ template firstSuccessParallel*(
         # This case could not be happened.
         error "Unexpected exception while waiting for beacon nodes",
               err_name = $exc.name, err_msg = $exc.msg
-        var default: seq[BeaconNodeServerRef]
+        default(seq[BeaconNodeServerRef])
-        default
 
     if len(onlineNodes) == 0:
       retRes = ApiResponse[handlerType].err("No online beacon node(s)")
@@ -183,15 +230,8 @@ template firstSuccessParallel*(
             let
               node {.inject.} = beaconNode
               apiResponse {.inject.} =
-                if timerFut.finished():
+                apiResponseOr[responseType](requestFut, timerFut,
-                  ApiResponse[responseType].err(
+                  "Timeout exceeded while awaiting for the response")
-                    "Timeout exceeded while awaiting for the response")
-                else:
-                  if requestFut.failed():
-                    ApiResponse[responseType].err($requestFut.error.msg)
-                  else:
-                    ApiResponse[responseType].ok(
-                      Future[responseType](requestFut).read())
               handlerResponse =
                 try:
                   body2
@@ -200,7 +240,7 @@ template firstSuccessParallel*(
                 except CatchableError:
                   raiseAssert("Response handler must not raise exceptions")
 
-            if apiResponse.isOk() and handlerResponse.isOk():
+            if handlerResponse.isOk():
               retRes = handlerResponse
               resultReady = true
               asyncSpawn lazyWait(pendingNodes, pendingRequests, timerFut,
@@ -213,7 +253,7 @@ template firstSuccessParallel*(
             pendingCancel.add(raceFut.cancelAndWait())
           if not(isNil(timerFut)) and not(timerFut.finished()):
             pendingCancel.add(timerFut.cancelAndWait())
-          for index, future in pendingRequests.pairs():
+          for future in pendingRequests.items():
             if not(future.finished()):
               pendingCancel.add(future.cancelAndWait())
           await allFutures(pendingCancel)
@@ -236,13 +276,16 @@ template firstSuccessParallel*(
 template bestSuccess*(
            vc: ValidatorClientRef,
            responseType: typedesc,
+           handlerType: typedesc,
            timeout: Duration,
            statuses: set[RestBeaconNodeStatus],
            roles: set[BeaconNodeRole],
            bodyRequest,
-           bodyScore: untyped): ApiResponse[responseType] =
+           bodyScore,
-  var it {.inject.}: RestClientRef
+           bodyHandler: untyped): ApiResponse[handlerType] =
-  type BodyType = typeof(bodyRequest)
+  var
+    it {.inject.}: RestClientRef
+    iterations = 0
 
   var timerFut =
     if timeout != InfiniteDuration:
@@ -250,114 +293,166 @@ template bestSuccess*(
     else:
       nil
 
-  let onlineNodes =
+  var
-    try:
+    retRes: ApiResponse[handlerType]
-      await vc.waitNodes(timerFut, statuses, roles, false)
+    scores: seq[ApiScore]
-      vc.filterNodes(statuses, roles)
+    bestResponse: Opt[BestNodeResponse[handlerType]]
-    except CancelledError as exc:
-      if not(isNil(timerFut)) and not(timerFut.finished()):
-        await timerFut.cancelAndWait()
-      raise exc
-    except CatchableError as exc:
-      # This case could not be happened.
-      error "Unexpected exception while waiting for beacon nodes",
-            err_name = $exc.name, err_msg = $exc.msg
-      var default: seq[BeaconNodeServerRef]
-      default
 
-  if len(onlineNodes) == 0:
+  block mainLoop:
-    ApiResponse[responseType].err("No online beacon node(s)")
+    while true:
-  else:
+      let onlineNodes =
-    let
-      (pendingRequests, pendingNodes) =
-        block:
-          var requests: seq[BodyType]
-          var nodes: seq[BeaconNodeServerRef]
-          for node {.inject.} in onlineNodes:
-            it = node.client
-            let fut = bodyRequest
-            requests.add(fut)
-            nodes.add(node)
-          (requests, nodes)
-
-      status =
         try:
-          if isNil(timerFut):
+          if iterations == 0:
-            await allFutures(pendingRequests)
+            # We are not going to wait for BNs if there some available.
-            ApiOperation.Success
+            await vc.waitNodes(timerFut, statuses, roles, false)
           else:
-            let waitFut = allFutures(pendingRequests)
+            # We get here only, if all the requests are failed. To avoid requests
-            discard await race(waitFut, timerFut)
+            # spam we going to wait for changes in BNs statuses.
-            if not(waitFut.finished()):
+            await vc.waitNodes(timerFut, statuses, roles, true)
-              await waitFut.cancelAndWait()
+          vc.filterNodes(statuses, roles)
-              ApiOperation.Timeout
-            else:
-              if not(timerFut.finished()):
-                await timerFut.cancelAndWait()
-              ApiOperation.Success
         except CancelledError as exc:
-          # We should cancel all the pending requests and timer before we return
-          # result.
-          var pendingCancel: seq[Future[void]]
-          for future in pendingRequests:
-            if not(fut.finished()):
-              pendingCancel.add(fut.cancelAndWait())
           if not(isNil(timerFut)) and not(timerFut.finished()):
-            pendingCancel.add(timerFut.cancelAndWait())
+            await timerFut.cancelAndWait()
-          await allFutures(pendingCancel)
           raise exc
-        except CatchableError:
+        except CatchableError as exc:
-          # This should not be happened, because allFutures() and race() did not
+          # This case could not be happened.
-          # raise any exceptions.
+          error "Unexpected exception while waiting for beacon nodes",
-          ApiOperation.Failure
+                err_name = $exc.name, err_msg = $exc.msg
+          default(seq[BeaconNodeServerRef])
 
-      apiResponses {.inject.} =
+      if len(onlineNodes) == 0:
-        block:
+        retRes = ApiResponse[handlerType].err("No online beacon node(s)")
-          var res: seq[ApiNodeResponse[responseType]]
+        break mainLoop
-          for requestFut, pnode in pendingRequests.pairs():
-            let beaconNode = pendingNodes[index]
-            if requestFut.finished():
-              if requestFut.failed():
-                let exc = requestFut.readError()
-                debug "One of operation requests has been failed",
-                      node = beaconNode, err_name = $exc.name,
-                      err_msg = $exc.msg
-                beaconNode.status.updateStatus(RestBeaconNodeStatus.Offline)
-              elif future.cancelled():
-                debug "One of operation requests has been interrupted",
-                      node = beaconNode
-              else:
-                res.add(
-                  ApiNodeResponse(
-                    node: beaconNode,
-                    data: ApiResponse[responseType].ok(future.read())
-                  )
-                )
-            else:
-              case status
-              of ApiOperation.Timeout:
-                debug "One of operation requests has been timed out",
-                      node = beaconNode
-                pendingNodes[index].status = RestBeaconNodeStatus.Offline
-              of ApiOperation.Success, ApiOperation.Failure,
-                 ApiOperation.Interrupt:
-                 # This should not be happened, because all Futures should be
-                 # finished.
-                debug "One of operation requests failed unexpectedly",
-                      node = beaconNode
-                pendingNodes[index].status = RestBeaconNodeStatus.Offline
-          res
-
-    if len(apiResponses) == 0:
-      ApiResponse[responseType].err("No successful responses available")
-    else:
-      let index = bestScore
-      if index >= 0:
-        debug "Operation request result was selected",
-              node = apiResponses[index].node
-        apiResponses[index].data
       else:
-        ApiResponse[responseType].err("Unable to get best response")
+        var
+          (pendingRequests, pendingNodes) =
+            block:
+              var requests: seq[FutureBase]
+              var nodes: seq[BeaconNodeServerRef]
+              for node {.inject.} in onlineNodes:
+                it = node.client
+                let fut = FutureBase(bodyRequest)
+                requests.add(fut)
+                nodes.add(node)
+              (requests, nodes)
+          perfectScoreFound = false
+
+        block innerLoop:
+          while len(pendingRequests) > 0:
+            var
+              finishedRequests: seq[FutureBase]
+              finishedNodes: seq[BeaconNodeServerRef]
+              raceFut: Future[FutureBase]
+            try:
+              raceFut = race(pendingRequests)
+
+              if isNil(timerFut):
+                await raceFut or timerFut
+              else:
+                await allFutures(raceFut)
+
+              for index, future in pendingRequests.pairs():
+                if future.finished() or
+                   (not(isNil(timerFut)) and timerFut.finished()):
+                  finishedRequests.add(future)
+                  finishedNodes.add(pendingNodes[index])
+                  let
+                    node {.inject.} = pendingNodes[index]
+                    apiResponse {.inject.} =
+                      apiResponseOr[responseType](future, timerFut,
+                        "Timeout exceeded while awaiting for the response")
+                    handlerResponse =
+                      try:
+                        bodyHandler
+                      except CancelledError as exc:
+                        raise exc
+                      except CatchableError:
+                        raiseAssert(
+                          "Response handler must not raise exceptions")
+
+                  if handlerResponse.isOk():
+                    let
+                      itresponse {.inject.} = handlerResponse.get()
+                      score =
+                        try:
+                          bodyScore
+                        except CancelledError as exc:
+                          raise exc
+                        except CatchableError:
+                          raiseAssert("Score handler must not raise exceptions")
+                    scores.add(ApiScore.init(node, score))
+                    if bestResponse.isNone() or
+                      (score > bestResponse.get().score):
+                      bestResponse = Opt.some(
+                        BestNodeResponse.init(node, handlerResponse, score))
+                      if perfectScore(score):
+                        perfectScoreFound = true
+                        break
+                  else:
+                    scores.add(ApiScore.init(node))
+
+              if perfectScoreFound:
+                # lazyWait will cancel `pendingRequests` on timeout.
+                asyncSpawn lazyWait(pendingNodes, pendingRequests, timerFut,
+                                    RequestName, strategy)
+                break innerLoop
+
+              if not(isNil(timerFut)) and timerFut.finished():
+                # If timeout is exceeded we need to cancel all the tasks which
+                # are still running.
+                var pendingCancel: seq[Future[void]]
+                for future in pendingRequests.items():
+                  if not(future.finished()):
+                    pendingCancel.add(future.cancelAndWait())
+                await allFutures(pendingCancel)
+                break innerLoop
+
+              pendingRequests.keepItIf(it notin finishedRequests)
+              pendingNodes.keepItIf(it notin finishedNodes)
+
+            except CancelledError as exc:
+              var pendingCancel: seq[Future[void]]
+              # `or` operation does not cancelling Futures passed as arguments.
+              if not(isNil(raceFut)) and not(raceFut.finished()):
+                pendingCancel.add(raceFut.cancelAndWait())
+              if not(isNil(timerFut)) and not(timerFut.finished()):
+                pendingCancel.add(timerFut.cancelAndWait())
+              # We should cancel all the requests which are still pending.
+              for future in pendingRequests.items():
+                if not(future.finished()):
+                  pendingCancel.add(future.cancelAndWait())
+              # Awaiting cancellations.
+              await allFutures(pendingCancel)
+              raise exc
+            except CatchableError as exc:
+              # This should not be happened, because allFutures() and race()
+              # did not raise any exceptions.
+              error "Unexpected exception while processing request",
+                    err_name = $exc.name, err_msg = $exc.msg
+              retRes = ApiResponse[handlerType].err("Unexpected error")
+              break mainLoop
+
+        if bestResponse.isSome():
+          retRes = bestResponse.get().data
+          break mainLoop
+        else:
+          if timerFut.finished():
+            retRes = ApiResponse[handlerType].err(
+                       "Timeout exceeded while awaiting for responses")
+            break mainLoop
+          else:
+            # When all requests failed
+            discard
+
+      inc(iterations)
+
+  if retRes.isOk():
+    debug "Best score result selected",
+          request = RequestName, available_scores = scores,
+          best_score = shortScore(bestResponse.get().score),
+          best_node = bestResponse.get().node
+
+  retRes
 
 template onceToAll*(
            vc: ValidatorClientRef,
@@ -1225,7 +1320,7 @@ proc produceAttestationData*(
   var failures: seq[ApiNodeFailure]
 
   case strategy
-  of ApiStrategyKind.First, ApiStrategyKind.Best:
+  of ApiStrategyKind.First:
     let res = vc.firstSuccessParallel(
       RestPlainResponse,
       ProduceAttestationDataResponse,
@@ -1266,6 +1361,47 @@ proc produceAttestationData*(
       raise (ref ValidatorApiError)(msg: res.error, data: failures)
     return res.get().data
 
+  of ApiStrategyKind.Best:
+    let res = vc.bestSuccess(
+      RestPlainResponse,
+      ProduceAttestationDataResponse,
+      OneThirdDuration,
+      ViableNodeStatus,
+      {BeaconNodeRole.AttestationData},
+      produceAttestationDataPlain(it, slot, committee_index),
+      getAttestationDataScore(vc, itresponse)):
+      if apiResponse.isErr():
+        handleCommunicationError()
+        ApiResponse[ProduceAttestationDataResponse].err(apiResponse.error)
+      else:
+        let response = apiResponse.get()
+        case response.status
+        of 200:
+          let res = decodeBytes(ProduceAttestationDataResponse, response.data,
+                                response.contentType)
+          if res.isErr():
+            handleUnexpectedData()
+            ApiResponse[ProduceAttestationDataResponse].err($res.error)
+          else:
+            ApiResponse[ProduceAttestationDataResponse].ok(res.get())
+        of 400:
+          handle400()
+          ApiResponse[ProduceAttestationDataResponse].err(ResponseInvalidError)
+        of 500:
+          handle500()
+          ApiResponse[ProduceAttestationDataResponse].err(ResponseInternalError)
+        of 503:
+          handle503()
+          ApiResponse[ProduceAttestationDataResponse].err(
+            ResponseNoSyncError)
+        else:
+          handleUnexpectedCode()
+          ApiResponse[ProduceAttestationDataResponse].err(
+            ResponseUnexpectedError)
+    if res.isErr():
+      raise (ref ValidatorApiError)(msg: res.error, data: failures)
+    return res.get().data
+
   of ApiStrategyKind.Priority:
     vc.firstSuccessSequential(
       RestPlainResponse,

beacon_chain/validator_client/common.nim

@@ -208,6 +208,7 @@ type
     dynamicFeeRecipientsStore*: ref DynamicFeeRecipientsStore
     validatorsRegCache*: Table[ValidatorPubKey, SignedValidatorRegistrationV1]
     blocksSeen*: Table[Slot, BlockDataItem]
+    rootsSeen*: Table[Eth2Digest, Slot]
     processingDelay*: Opt[Duration]
     rng*: ref HmacDrbgContext
 
@@ -1207,23 +1208,25 @@ proc expectBlock*(vc: ValidatorClientRef, slot: Slot,
   if not(retFuture.finished()): retFuture.cancelCallback = cancellation
   retFuture
 
-proc registerBlock*(vc: ValidatorClientRef, data: EventBeaconBlockObject,
+proc registerBlock*(vc: ValidatorClientRef, eblck: EventBeaconBlockObject,
                     node: BeaconNodeServerRef) =
   let
     wallTime = vc.beaconClock.now()
-    delay = wallTime - data.slot.start_beacon_time()
+    delay = wallTime - eblck.slot.start_beacon_time()
 
-  debug "Block received", slot = data.slot,
+  debug "Block received", slot = eblck.slot,
-        block_root = shortLog(data.block_root), optimistic = data.optimistic,
+        block_root = shortLog(eblck.block_root), optimistic = eblck.optimistic,
         node = node, delay = delay
 
   proc scheduleCallbacks(data: var BlockDataItem,
                          blck: EventBeaconBlockObject) =
+    vc.rootsSeen[blck.block_root] = blck.slot
     data.blocks.add(blck.block_root)
     for mitem in data.waiters.mitems():
       if mitem.count >= len(data.blocks):
         if not(mitem.future.finished()): mitem.future.complete(data.blocks)
-  vc.blocksSeen.mgetOrPut(data.slot, BlockDataItem()).scheduleCallbacks(data)
+
+  vc.blocksSeen.mgetOrPut(eblck.slot, BlockDataItem()).scheduleCallbacks(eblck)
 
 proc pruneBlocksSeen*(vc: ValidatorClientRef, epoch: Epoch) =
   var blocksSeen: Table[Slot, BlockDataItem]
@@ -1231,6 +1234,7 @@ proc pruneBlocksSeen*(vc: ValidatorClientRef, epoch: Epoch) =
     if (slot.epoch() + HISTORICAL_DUTIES_EPOCHS) >= epoch:
       blocksSeen[slot] = item
     else:
+      for root in item.blocks: vc.rootsSeen.del(root)
       let blockRoot =
         if len(item.blocks) == 0:
           "<missing>"

beacon_chain/validator_client/scoring.nim

@@ -0,0 +1,49 @@
+# beacon_chain
+# Copyright (c) 2023 Status Research & Development GmbH
+# Licensed and distributed under either of
+#   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
+#   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
+# at your option. This file may not be copied, modified, or distributed except according to those terms.
+
+import std/strutils
+import "."/common
+
+{.push raises: [].}
+
+func perfectScore*(score: float64): bool =
+  score == Inf
+
+proc shortScore*(score: float64): string =
+  if score == Inf: "<perfect>" else: formatFloat(score, ffDecimal, 4)
+
+proc getAttestationDataScore*(rootsSeen: Table[Eth2Digest, Slot],
+                              adata: ProduceAttestationDataResponse): float64 =
+  let
+    slot = rootsSeen.getOrDefault(
+      adata.data.beacon_block_root, FAR_FUTURE_SLOT)
+
+  let res =
+    if (slot == adata.data.slot) and
+       (adata.data.source.epoch + 1 == adata.data.target.epoch):
+      # Perfect score
+      Inf
+    else:
+      let score = float64(adata.data.source.epoch) +
+                  float64(adata.data.target.epoch)
+      if slot == FAR_FUTURE_SLOT:
+        score
+      else:
+        if adata.data.slot + 1 == slot:
+          # To avoid `DivizionByZero` defect.
+          score
+        else:
+          score + float64(1) / (float64(adata.data.slot) + float64(1) -
+                                float64(slot))
+
+  debug "Attestation score", attestation_data = shortLog(adata.data),
+        block_slot = slot, score = shortScore(res)
+  res
+
+proc getAttestationDataScore*(vc: ValidatorClientRef,
+                              adata: ProduceAttestationDataResponse): float64 =
+  getAttestationDataScore(vc.rootsSeen, adata)

tests/test_validator_client.nim

@@ -10,7 +10,7 @@
 
 import std/strutils
 import unittest2
-import ../beacon_chain/validator_client/common
+import ../beacon_chain/validator_client/[common, scoring]
 
 const
   HostNames = [
@@ -143,9 +143,110 @@ const
     ("", "err(Missing hostname)")
   ]
 
+type
+  AttestationDataTuple* = tuple[
+    slot: uint64,
+    index: uint64,
+    beacon_block_root: string,
+    source: uint64,
+    target: uint64
+  ]
+
+const
+  AttestationDataVectors = [
+    # Attestation score with block monitoring enabled (perfect).
+    ((6002798'u64, 10'u64, "22242212", 187586'u64, 187587'u64),
+     ("22242212", 6002798'u64), "<perfect>"),
+    ((6002811'u64, 24'u64, "26ec78d6", 187586'u64, 187587'u64),
+     ("26ec78d6", 6002811'u64), "<perfect>"),
+    ((6002821'u64, 11'u64, "10c6d1a2", 187587'u64, 187588'u64),
+     ("10c6d1a2", 6002821'u64), "<perfect>"),
+    ((6002836'u64, 15'u64, "42354ded", 187587'u64, 187588'u64),
+     ("42354ded", 6002836'u64), "<perfect>"),
+    ((6002859'u64, 10'u64, "97d8ac69", 187588'u64, 187589'u64),
+     ("97d8ac69", 6002859'u64), "<perfect>"),
+    # Attestation score with block monitoring enabled #1 (not perfect).
+    ((6002871'u64, 25'u64, "524a9e2b", 187588'u64, 187589'u64),
+     ("524a9e2b", 6002870'u64), "375177.5000"),
+    ((6002871'u64, 25'u64, "524a9e2b", 187588'u64, 187589'u64),
+     ("524a9e2b", 6002869'u64), "375177.3333"),
+    ((6002871'u64, 25'u64, "524a9e2b", 187588'u64, 187589'u64),
+     ("524a9e2b", 6002868'u64), "375177.2500"),
+    ((6002871'u64, 25'u64, "524a9e2b", 187588'u64, 187589'u64),
+     ("524a9e2b", 6002867'u64), "375177.2000"),
+    ((6002871'u64, 25'u64, "524a9e2b", 187588'u64, 187589'u64),
+     ("524a9e2b", 6002866'u64), "375177.1667"),
+    # Attestation score with block monitoring enabled #2 (not perfect).
+    ((6002962'u64, 14'u64, "22a19d87", 187591'u64, 187592'u64),
+     ("22a19d87", 6002961'u64), "375183.5000"),
+    ((6002962'u64, 14'u64, "22a19d87", 187591'u64, 187592'u64),
+     ("22a19d87", 6002960'u64), "375183.3333"),
+    ((6002962'u64, 14'u64, "22a19d87", 187591'u64, 187592'u64),
+     ("22a19d87", 6002959'u64), "375183.2500"),
+    ((6002962'u64, 14'u64, "22a19d87", 187591'u64, 187592'u64),
+     ("22a19d87", 6002958'u64), "375183.2000"),
+    ((6002962'u64, 14'u64, "22a19d87", 187591'u64, 187592'u64),
+     ("22a19d87", 6002957'u64), "375183.1667"),
+    # Attestation score with block monitoring disabled #1.
+    ((6003217'u64, 52'u64, "5e945218", 187599'u64, 187600'u64),
+     ("00000000", 0'u64), "375199.0000"),
+    ((6003217'u64, 52'u64, "5e945218", 187598'u64, 187600'u64),
+     ("00000000", 0'u64), "375198.0000"),
+    ((6003217'u64, 52'u64, "5e945218", 187597'u64, 187600'u64),
+     ("00000000", 0'u64), "375197.0000"),
+    ((6003217'u64, 52'u64, "5e945218", 187596'u64, 187600'u64),
+     ("00000000", 0'u64), "375196.0000"),
+    ((6003217'u64, 52'u64, "5e945218", 187595'u64, 187600'u64),
+     ("00000000", 0'u64), "375195.0000"),
+    # Attestation score with block monitoring disabled #2.
+    ((6003257'u64, 9'u64, "7bfa464e", 187600'u64, 187601'u64),
+     ("00000000", 0'u64), "375201.0000"),
+    ((6003257'u64, 9'u64, "7bfa464e", 187599'u64, 187601'u64),
+     ("00000000", 0'u64), "375200.0000"),
+    ((6003257'u64, 9'u64, "7bfa464e", 187598'u64, 187601'u64),
+     ("00000000", 0'u64), "375199.0000"),
+    ((6003257'u64, 9'u64, "7bfa464e", 187597'u64, 187601'u64),
+     ("00000000", 0'u64), "375198.0000"),
+    ((6003257'u64, 9'u64, "7bfa464e", 187596'u64, 187601'u64),
+     ("00000000", 0'u64), "375197.0000"),
+  ]
+
+proc init(t: typedesc[Eth2Digest], data: string): Eth2Digest =
+  let length = len(data)
+  var dst = Eth2Digest()
+  try:
+    hexToByteArray(data.toOpenArray(0, len(data) - 1),
+                   dst.data.toOpenArray(0, (length div 2) - 1))
+  except ValueError:
+    discard
+  dst
+
+proc init*(t: typedesc[ProduceAttestationDataResponse],
+           ad: AttestationDataTuple): ProduceAttestationDataResponse =
+  ProduceAttestationDataResponse(data: AttestationData(
+    slot: Slot(ad.slot), index: ad.index,
+    beacon_block_root: Eth2Digest.init(ad.beacon_block_root),
+    source: Checkpoint(epoch: Epoch(ad.source)),
+    target: Checkpoint(epoch: Epoch(ad.target))
+  ))
+
+proc createRootsSeen(
+       root: tuple[root: string, slot: uint64]): Table[Eth2Digest, Slot] =
+  var res: Table[Eth2Digest, Slot]
+  res[Eth2Digest.init(root.root)] = Slot(root.slot)
+  res
+
 suite "Validator Client test suite":
   test "normalizeUri() test vectors":
     for hostname in HostNames:
       for vector in GoodTestVectors:
         let expect = vector[1] % (hostname)
         check $normalizeUri(parseUri(vector[0] % (hostname))) == expect
+
+  test "getAttestationDataScore() test vectors":
+    for vector in AttestationDataVectors:
+      let
+        adata = ProduceAttestationDataResponse.init(vector[0])
+        roots = createRootsSeen(vector[1])
+        score = shortScore(roots.getAttestationDataScore(adata))
+      check score == vector[2]